The fundamental role of habitat management in wildlife conservation
We often talk about how to manage wildlife populations, and we’ve even discussed these topics in some length here (What exactly is wildlife management, What happens if we stop managing wildlife and ban hunting, The crucial role of predators and predator management ). However, we quite often fail to fully discuss one of the most important topics: what are the requirements for having a specific type of game on our land, what are the features of the habitat they require and what should we do to get the most out of our land?
So, in this article, we are going to take a look at what habitat actually is and how important good habitat management is when managing our game populations.
OK, let’s set the scene
Whether for residence, for agriculture, for commerce, for recreation or for transportation, humans have (obviously) been utilizing the land from year dot.
Now, the Earth’s surface area only consists of 29% land, the remaining 71% is ocean. Of the land’s surface, 71% is currently defined as habitable for humans; the remaining 29% is made up of glaciers and barren land.
To compound matters, over the last 100 years, the global population has more than quadrupled and is expected to continue to grow. Unfortunately, this means we are increasing the pressure on the planet and using more and more of the Earth’s resources.
And, importantly, it is not just ours - we share the land.
So, in order to live sustainably, harmoniously, and successfully side by side with animals, we need to focus on how to share the land and its resources, and importantly, to ensure animals have the space and resources they need.
What is a habitat?
We all have basic requirements that need to be fulfilled in order to live and grow. Like people, animals also need a certain place and certain conditions to survive. The area that provides the necessary resources and environmental conditions is called the habitat. Generally, the habitat is where the animal lives. However, the term “habitat” should not be confused when describing a particular vegetation community or general physical environment, e.g. Black pine habitat or wetland habitat, as these are habitat types.
...All animals, except humans, are restricted to a certain area....
All animals, except humans, are restricted to certain areas - humans, have access to all necessary resources from all over the planet and that’s why we occupy nearly all the land surfaces on the planet.
The needs of the game
The habitat is a species-specific concept as each species has its own unique requirements. Of course, two or more species might share the same habitat, but their specific needs are likely different, and therefore, changes in the environment will affect them differently.
The resources or habitat factors that all animals need include food, water, cover and space along with the right environmental conditions like temperature, soil type, precipitation, etc.
The environmental conditions are divided into biotic (living) and abiotic (non-living) factors.
The most important abiotic factors are light, temperature, water supply, air (movement) and mineral supply in the soil for the vegetation; these are also called the general ecological features.
Biotic factors are living organisms that affect other organisms or shape the environment.
How and why do species select their habitat?
Each species has a tolerance range for certain abiotic environmental factors and can only live and manoeuvre within this range. This can be pictured as a bell shaped curve that has a minimum, optimum and maximum.
The given species will tolerate the minimum or maximum, but most individuals within a species are found in the optimum condition and in this environment, the largest population growth will be seen. This principle is called Shelford’s Law of Tolerance.
...It is the scarcest resource that determines the growth and the development of the population and not the total resources available...
When habitat factors are in good supply, they contribute to the wellbeing of wildlife. However, if any of the habitat factors are in short supply, be it not enough food, water or nesting places, it will limit the number and distribution of wildlife in a given area (the limiting factor).
In fact, the scarcest resource determines the growth and the development of the population and not the total resources available. This principle is Liebig’s Law of the Minimum, which is originally used in agriculture to showcase the amount of nutrients in the soil; the least amount of a nutrient will cause the yield to be lower, even if other nutrients are plentiful.
However, when referring to wildlife, most game managers will immediately think about the amount of food in an area, though this principle can be interpreted for all environmental conditions.
The effect of humankind
...The greatest threat to species diversity overall, has not been trophy hunting, as many people think, but rather habitat loss and degradation...
Unfortunately, human activities on habitats have been disastrous - urbanization, eliminating predators and competitors, repopulating the planet with domestic animals, moving “familiar” animals across the world, habitat destruction (e.g. the recent burning of the Amazon forest and the fires in Africa), human population growth and pollution have all put the survival of wildlife in danger.
Some areas have been subjected to human-induced changes we simply cannot reverse, for example, climate change, acidification of soil and water bodies, changes in the species composition due to the introduction of alien or exotic species etc.
In these circumstances, it is more about the process of adapting and managing these changes as opposed to building a new habitat or trying to undo these changes. Therefore, we have to focus on minimizing the negative effects and maximizing the positive ones.
For a lot of species the number one threat, and the greatest threat to species diversity overall, has not been trophy hunting, as many people think, but habitat loss and degradation because of the constantly growing human population and its needs.
The role of habitat management in wildlife conservation
In order to conserve wildlife, we need to focus more on wildlife’s needs instead of our own and this is where we, as wildlife biologists, game managers and landowners, need to influence habitats by managing (positively manipulating) the resources we can provide for them.
These resources are:
- Food – both quantity and quality are important
- Cover – this is necessary for protection during feeding, sleeping, playing, breeding, roosting, nesting, moving around, etc.
- Water – this includes surface water, dew, snow and juicy vegetation
- Space – this focuses on overcrowding which can lead to severe competition between individuals and the population will suffer as only a specific number of animals can live in any one area
…Vegetation is the core component of the habitat, the main factor to focus on...
Consequently, habitat management can be defined as influencing the successional stage and physical structure of vegetation to benefit particular (or assemblages of) species considered to be of high conservation or other intrinsic value.
As vegetation is the core component of the habitat of terrestrial vertebrates it is the main factor of focus. (Ecological) succession is the process in which plants and animals change over time in the absence of disturbance, and by intervening in this process we can either increase or decrease the habitat quality.
However, besides habitat management there is also habitat improvement and habitat restoration.
So, what’s the difference?
When we improve a habitat, we manage it so it will be better than before, for example by providing more food or cover.
Restoring a habitat is to manage it to how it was before. This can be because of habitat degradation or damage. A good example for this is when there were still great plains in the past that consisted of a high biodiversity that have been now transferred to intensified agricultural areas with large monocultures. These lands could be hundreds of hectares large and cannot provide the necessary resources for an animal that lives only on a fraction of this area. This is the case for a lot of small game animals that now suffer the consequences of these agricultural changes.
The basic rule of habitat management is the edges
...When we manage habitats, we need to focus on creating edges...
Moreover, not only is it the amount of resources that count, but also their distribution within the habitat. The arrangement of food, cover and water in an area determines wildlife numbers and their distribution. It’s most effective when the habitat factors occur in combinations of small blocks that are close together.
It is also important to note that wildlife lives along the edges, not in the centres of different types of vegetation growing in an area. The edge is where two types of vegetation meet, and when wildlife concentrates to these areas, it’s called the edge effect. Therefore, when we manage habitats, we need to focus on creating edges.
Dos & Don’ts in habitat management
...Different species have different needs...
In order to start managing a habitat, it is necessary to gain knowledge of the environmental conditions and the resources needed for a certain species first. After this, we can develop a strategy to meet habitat-based conservation and management goals.
Also, we cannot increase the number of all species on every piece of land as when we manage a piece of land for a certain species, we will always manage against other species.
Please keep in mind that the different species have different needs (see chapter: The needs of the game). Therefore, you have to take into consideration whether you are managing the habitat for small or big game and for which species.
The basic rules are as follows: don’t forget the 4 factors of habitat management (food, water, cover, space).
Let’s see some practical examples of habitat management that help provide suitable habitat for wildlife.
- Don’t use fertilizer, herbicides and other chemicals at the edge of fields
- Don’t remove bushes or old/stand-alone trees to make land appear more “tidy”
- Don’t let unwanted plants grow and spread
- Don’t let livestock graze the areas set aside for wildlife
- Don’t let predators overhunt the species you would like to conserve
- Food: plant food for wildlife – this can be grains, fruit-bearing bushes, grasses, legumes, etc.
- Water: create a pond or other wetland area – this provides water and plant species (e.g. willows and cattails) that make good wildlife habitat
- Cover: building brush piles or establishing woody thickets to provide cover
- Space: keep the population under control - monitor the species and the population size and the quality of the game
Of course, there are more species-specific guides about habitat management, for example the “Providing nesting cover for wild grey partridges” Fact sheet form Game and Wildlife Conservation Trust.
You can visit the GWCT website for more practical guides in habitat management for specific species.
...We have to take responsibility for our species...
Habitat management is basically an indirect way of managing wildlife, moreover, it is fundamental to the survival of species and long term conservation.
We should always remember that we are a part of the ecological community and not above it and because we have the ability to control and make changes in the wildlife populations we have to take responsibility for our species and the land we share.
Sources and further readings:
Malcolm Ausden. 2007. Habitat Management for Conservation. Oxford University Press, UK
Michael L. Morrison, Bruce Marcot and William Mannan. 2006. Wildlife-Habitat Relationships: Concepts and Applications 3rd Edition. Island Press, London
Paul R. Krausman and James W. Cain. 2013. Wildlife Management and Conservation: Contemporary Principles and Practices 3rd Edition. The Johns Hopkins University Press, Baltimore, Maryland